/*
 * ProGuard -- shrinking, optimization, obfuscation, and preverification of Java bytecode.
 *
 * Copyright (c) 2002-2018 GuardSquare NV
 *
 * This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later
 * version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along with this program; if not, write to the Free
 * Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
package proguard.classfile.constant;

import proguard.classfile.*;
import proguard.classfile.constant.visitor.ConstantVisitor;

/**
 * This Constant represents a method handle constant in the constant pool.
 *
 * @author Eric Lafortune
 */
public class MethodHandleConstant extends Constant {
    public int u1referenceKind;
    public int u2referenceIndex;

    /**
     * An extra field pointing to the java.lang.invoke.MethodHandle Clazz object. This field is typically filled out by
     * the <code>{@link
     * proguard.classfile.util.ClassReferenceInitializer
     * ClassReferenceInitializer}</code>.
     */
    public Clazz javaLangInvokeMethodHandleClass;

    /**
     * Creates an uninitialized MethodHandleConstant.
     */
    public MethodHandleConstant() {}

    /**
     * Creates a new MethodHandleConstant with the given type and method ref index.
     * 
     * @param u1referenceKind the reference kind.
     * @param u2referenceIndex the index of the field ref constant, interface method ref constant, or method ref
     *        constant in the constant pool.
     */
    public MethodHandleConstant(int u1referenceKind, int u2referenceIndex) {
        this.u1referenceKind = u1referenceKind;
        this.u2referenceIndex = u2referenceIndex;
    }

    /**
     * Returns the kind of reference to which this constant is pointing.
     * 
     * @return One of {@link ClassConstants#REF_getField }, {@link ClassConstants#REF_getStatic },
     *         {@link ClassConstants#REF_putField }, {@link ClassConstants#REF_putStatic },
     *         {@link ClassConstants#REF_invokeVirtual }, {@link ClassConstants#REF_invokeStatic },
     *         {@link ClassConstants#REF_invokeSpecial }, {@link ClassConstants#REF_newInvokeSpecial}, or
     *         {@link ClassConstants#REF_invokeInterface }.
     */
    public int getReferenceKind() {
        return u1referenceKind;
    }

    /**
     * Returns the field ref, interface method ref, or method ref index.
     */
    public int getReferenceIndex() {
        return u2referenceIndex;
    }

    /**
     * Returns the class name.
     */
    public String getClassName(Clazz clazz) {
        return clazz.getRefClassName(u2referenceIndex);
    }

    /**
     * Returns the method/field name.
     */
    public String getName(Clazz clazz) {
        return clazz.getRefName(u2referenceIndex);
    }

    /**
     * Returns the type.
     */
    public String getType(Clazz clazz) {
        return clazz.getRefType(u2referenceIndex);
    }

    // Implementations for Constant.

    public int getTag() {
        return ClassConstants.CONSTANT_MethodHandle;
    }

    public void accept(Clazz clazz, ConstantVisitor constantVisitor) {
        constantVisitor.visitMethodHandleConstant(clazz, this);
    }
}
